U.S. legislators of both parties are condemning the burning of a Quran by a radical American Christian pastor, an act that has provoked deadly protests in Afghanistan.

Afghan demonstrators continue to seethe over last month’s burning of the Muslim holy book by Florida pastor Terry Jones. President Obama has condemned the act, as well as the violent reaction to it. Sunday, U.S. legislators took to America’s airwaves to echo the message.

"Religious extremism in any form is wrong. And certainly all these deaths [are] wrong. I am very, very disappointed that this man [Jones] decided to do this. I think people should understand the consequences of what they do under the guise of religion."

Appearing on NBC’s Meet the Press program, Democratic Senator Richard Durbin of Illinois urged Americans to exercise freedom of expression - a constitutionally-guaranteed right - in a responsible and thoughtful manner.

"I understand what the First Amendment [to the Constitution] says, the rights that are given to American citizens when it comes to speech and assembly and religion. But I want to tell you that this pastor with his publicity stunt with the Quran unfortunately endangers the lives of our troops and a lot of innocent people. It is time for him to accept the responsibility as an American to help our troops be safe."

The U.S. Constitution guarantees the right to almost all forms of non-violent expression, including speech and actions that others find offensive. As a result, groups that preach hate for minorities may hold marches and other public events. The Supreme Court has repeatedly affirmed the right to burn the American flag. It recently upheld the right of a fanatical Christian sect to launch hurtful diatribes at the funerals of fallen American soldiers. Constitutional scholars argue that any erosion of the freedom to express unpopular views would also erode religious freedom.

But with rights come responsibilities in a free society, according to Republican Senator Lindsey Graham of South Carolina, who spoke on Face the Nation.

"I wish we could find some way to hold people accountable. Free speech is a great idea, but we are in a war. During World War II, you had limits on what you could say if it would inspire the enemy. So, burning the Quran is a terrible thing, but it doesn’t justify killing someone. Burning a Bible would be a terrible thing, but it doesn’t justify murder."

Pastor Jones has said Islam must be "held accountable" for terrorism, and that his actions are meant to underscore that belief.

Senator Durbin suggests the best way to deal with Jones is to ignore him. "He is looking for publicity. And as long as he gets that publicity, he will continue this irresponsible conduct," he said.

Jones first threatened to burn the Quran to coincide with last year’s anniversary of the September 11, 2001, terrorist attacks on the United States. Days later, he announced he would not do so, but reserved the right to burn a Quran at a later date.